Collection

Demo: collection-demo

Vector: Vec<T>

• A collection of the same data type.

• The elements are stored in order.

• The elements are added or removed dynamically.

  An array has a fixed size.

• It's stored on the heap.

HashMap: HashMap<K, V>

• It stores the data in key-value pair.

• All the key or value must have the same type.

Update a key-value pair

• override the existing one

   scores.insert(String::from("Blue"), 25);
  

• create a new pair if it doesn't exist

  scores.entry(String::from("Green")).or_insert(50);
  

• modify the pair based on current state

  let blue_team_score = scores.entry(String::from("Blue")).or_insert(0);
  *blue_team_score += 10;